1. Field of the Invention
The present invention relates to an optical fiber structure in which a plurality of optical fiber arrays, each including a plurality of multimode optical fibers, are placed one on another.
2. Description of the Related Art
Conventionally, laser light has been used in the fields of printing and processing. For example, in production of printing blocks as described in U.S. Pat. No. 6,857,365, the laser light is used to process materials to produce print blocks. In recent years, high-output semiconductor lasers have been developed. Further, optical fiber structures that transmit high-output laser light, which is output from the high-output semiconductor lasers, through fibers and output the transmitted light are known. Further, in the field of optical fiber structures that are used in processing as described above, multicore-type optical fiber structures in which a plurality of optical fibers are fixed in such a manner that one-side ends thereof are arranged in line form or in block form are being developed to improve the processing efficiency.
When the laser light is used to process the print blocks as described in U.S. Pat. No. 6,857,365, there are cases in which laser light that has a small beam diameter is desirable and cases in which laser light that has a large beam diameter is desirable, depending on processing conditions. For example, when a highly-precise process should be carried out, the laser light that has a small diameter is desirable. In contrast, when a so-called solid processing should be performed, in other words, when the entire area of a certain area should be processed uniformly, the laser light that has a large diameter is desirable. However, in the conventional multicore-type optical fiber structure, there is a problem that it is impossible to change the beam diameter based on the processing conditions, because the multicore-type optical fiber structure includes a plurality of same optical fibers, which output beams having the same beam diameter. Meanwhile, there is an apparatus that changes the beam diameter of laser light by a special optical system provided in a later stage. However, there is a problem that such an optical system tends to be complex.